Thai people just can't stay away from khao gaeng, or rice-and-side-dish shops. It's like a relative they have to see everyday. Most Thai people eat rice with side dishes for at least one meal a day. This is why these shops are everywhere. A shop in a good location, close to the office and transportation hubs and that offers lots of options can quickly gain in popularity.

Various foods ready for sale. Suthon Sukphisit

These eateries know when to open -- whether for breakfast or lunch -- to get the crowd. They also know which dishes go best with each other. Spicy food also needs another dish to tone down the hotness. For example, a yellow curry should be paired with an omelette. Owners also have to consider the amount of tables to accommodate their customers.

In the markets, khao gaeng is sold at stalls that usually offer as many variety of dishes as the shops. The difference is these stalls only sell takeaway, ready-to-eat dishes neatly packed in plastic bags. A general practice is to sell in the afternoon to early evening so people can buy dishes to eat at home after finishing work.

Let me introduce an amazing Thai restaurant that presents about 10 dishes at the market beginning at 4pm. Their food is generally sold out within 90 minutes. Many question how the shop could be so successful, and whether the food is different from any other Thai food. How did they manage marketing and customer service? Do they perceive the khao gaeng shop and its takeaway counterparts differently?

Anchalee Amnuaypanich and Vilaisri Hongsangchai operate this eatery in the Sam Khok market in Pathum Thani. The sisters, ethnic Mon, grew up in the Bang Toey community along the Chao Phraya river where their mother sold hor mok (steamed Thai fish custard) and fried fish cakes in front of their shophouse inside the market. Later, the mother sold chicken green curry, pla raa lon (fermented fish dip), and soup. Most of her customers were local or civil servants who worked at the old Sam Khok district office near the river.

Spicy curry with roasted duck. Suthon Sukphisit

Later on, the neighbourhood prospered once modern roads were constructed, bringing more shops and markets along the main roads, squeezing vendors at the Bang Toey market. The family's income dwindled.

They then moved to a fresh market behind the nearby Bang Toey temple, which was open on Mondays, Thursdays and Saturdays. There they sold a variety of food, and business went better.

Later, a new modern market with a big roof and ample parking space opened not far from the previous one and right by the main road. The new market was called Sam Khok and the family decided to move there. Business picked up too. They sold 10-12 different types of side dishes such as spicy curry, sour soup and spicy stir-fry. They rotated dishes with a different menu each day. Green curry with chicken gave way to pineapple curry with mussels; gaeng khilek (curry with Siamese senna) with grilled pork switched to gaeng bon (curry with elephant ear). For gaeng som, or sour soup with tamarind paste, there were different combinations of ingredients, such as vegetables, papaya, roselle and shrimp. For clear soup, vermicelli, tofu or pork rib would be added. For spicy salad, there was vermicelli, grilled pork, and chicken with banana blossoms as options.

On certain days, they offered special Mon dishes like gaeng look matad and kaochae mon, which are seasonal. Also kanom jeen nam prik and gaeng hua looktarn would be on offer.

Vilaisri Hongsangchai preparing food. Suthon Sukphisit

The cooking process starts in the morning. The sisters would delegate tasks in preparing the food. By 3pm, everything is finished and ready for business.

The sisters also operate a sizeable Line group. Menus are published in the group daily before noon. This way, customers can know in advance what food is served and can reserve what they want. It's all for customer convenience. Customers often finish work late, and by the time they arrive at the shop, food may have already sold out. By then they won't be able to buy their favourite dishes.

Before the sisters leave their house, they package all the pre-ordered dishes inside a bag with a name tag. Customers can pick up their order any time. If the sisters have to leave early, they can leave the food with a neighbouring vendor. Payment is not a big problem. Customers can pay later at any time. This is one system that has proven to work well.

Many have wondered why they don't open a proper shop instead of just selling takeaway food. Selling takeaway simplifies their lives. They only have to cook once in the morning and sell in the afternoon. Each person has their own responsibility. Anchalee cooks and Vilaisri sells.

This is a story of takeaway food vendors who are successful, experienced and talented. They have an established system when it comes to setting up a menu and a modern customer service approach. The fresh market is ever a prime location as most locals shop there.